微束等离子多层熔覆NiCrBSi的试验研究  

Experimental study on NiCrBSi multilayer coating cladded by micro-plasma arc cladding process

作　　者：夏丹[1] 徐滨士[1] 吕耀辉[1] 向永华[1] 刘存龙[1] 

机构地区：[1]装备再制造技术国防科技重点实验室,北京100072

出　　处：《材料科学与工艺》2009年第5期645-648,共4页Materials Science and Technology

基　　金：国家自然科学基金资助项目(50675223);装备再制造技术国防科技重点实验室基金项目(9140C85020206JS9105)

摘　　要：为了在降低熔覆层裂纹敏感性的同时获得低稀释率熔覆层,用微束等离子弧热源在低碳钢圆管表面熔覆12层NiCrBSi,成形后利用扫描电镜(SEM)、能谱仪(EDS)和X射线衍射仪(XRD)对多层熔覆的熔覆层的微观组织、元素分布及相组成进行了分析.结果表明,采用微束等离子弧熔覆得到的多层熔覆主要由γ-Ni,Ni3B,Cr21.34Fe1.66C6和Cr2B3相组成,其中的强化相弥散分布;无气孔和裂纹,层与层间结合致密,分层未见明显;焊缝组织均匀,晶粒细小,稀释率低,热影响区很小.In order to lower the crack sensitivity and obtain the coating with low dilution rate,micro-plasma are cladding process was employed to clad a 12-layer NiCrBSi coating on the surface of low carbon steel pipe. Scanning electron microscopy （ SEM）, energy dispersive spectroscopy （EDS） and X-ray diffraction （XRD） were employed to analyze the composition and microstructure of the coating. Results show that the phase of the coating is composed of 3＇- Ni solid solution, nickel boride Ni3B, carbide Cr21.34Fe1.66C6 and Cr2B3 type chromium boride. The coating has no cracks and does not exhibit porosity; the bonding between layers is compact and the boundaries are not observed. The coating is featured by a homogenized microstructure, small grain and no evident heat-affected zone.

关 键 词：NiCrBSi粉末 微束等离子 多层熔覆 

分 类 号：TG439.2[金属学及工艺—焊接]